As Anne has said, you can gamble without doing great damage, and most certainly the phrase "More bookies in the High Streets of the UK than shops now" is utter tosh.
Sure, there are some problem gamblers, but the numbers are DWARFED by the number of problem eaters, and problem drinkers! The eaters and drinkers also tend to kill themselves, having on the way cost the NHS huge sums trying to fix THOSE particular addictions (which the taxes from gambling are helping to pay for!). Oh, and drunk drivers tend to kill people, people who've overdosed playing roulette (etc) largely don't? Let's ban excess food and drink, have Big Brother checking your Tesco till rolls?!
TV adverts? Yes, look closely, and you will see them festooned with signs about 'GamCare', 'BetResponsibly' (etc etc).
Horse-racing is one of the largest employers in the country, apparently, when you add in all the ancillary business interests (hospitality, transport, etc), and trying to cripple it would be thoroughly counter-productive. And as some have said, it can be a nice day out (maybe don't go on a wet day like we've had so much of lately?!).
The REAL problem apparently lies with online games, roulette, poker, etc, which the campaign to not drastically increase taxes on horseracing tried to focus on. Those sites it seems, according to the article I read, are based outside of the UK, in low-tax locations (Gib, Malta, etc) so hard to enforce UK laws on them. If you have bright ideas about that, send to your MP?
Ban gambling because it's a terrible thing? Well, the numbers suggest it's hugely popular. Lots of countries abroad have horse-racing, France, Germany, Spain, Italy and plenty more, massive amounts in the States, Oz, Hong Kong, SA, and these days in S America too. Those countries tend to have a 'Tote' Based system, with the profits going to racing, or perhaps good causes.
I read years ago that THIS country messed up when betting shops appeared, the MacMillan Govt (Tories!) allowed itself to be 'persuaded' (the polite term?!) to let them be run by commercial interests, and so Ladbrokes, Corals, etc built vast business empires from the profits. We could only guess if any recently ex-politicos found themselves as directors of such firms?!